Alongside waste minimisation and segregation, the other key issue in medical waste management is how best to treat the unavoidable waste.

In the past, incineration was the technology of choice but it inevitably produces dioxin, one of the most toxic and persistent pollutants known to science — and most industrialised countries insist on complex and costly control measures to capture it. The resulting waste, such as fly ash, then must be disposed of as hazardous waste.

The scale of the problem is amply illustrated by the fact that, in 1994, the US Environmental Protection Agency announced that medical waste incinerators were responsible for 40% of the entire country's air dioxin pollution.

Most incinerators in the Global South have few or no pollution control devices, and so will release large quantities of dioxin, which can then enter the food chain. In rural areas where the smallest and most polluting incinerators are often found, it's not uncommon to see chickens scratching in the dust where the ash has been dumped — with the result that dioxin ends up transferred to their eggs. Dairy products are also particularly vulnerable to contamination of this type.

Part of the problem is that medical waste often contains a lot of PVC, and the chlorine in it is a vital ingredient in dioxin. Because of this, the World Health Organisation recommends that PVC waste not be incinerated; and Indian legislation rules it out entirely. For more information, see our PVC section.

The Stockholm Convention, which has been signed by over 150 countries, requires that best environmental practices and best available technologies are used to reduce the amount of dioxin from incineration.

There is ample proof that this can be done. In the last 20 years, the US has closed 99% of its medical waste incinerators, going from over 6,000 in 1988 to fewer than 60 at the end of 2008.

The Philippines demonstrates that is possible to eliminate incineration totally. In the cities, infectious waste is dealt with by centralised facilities running autoclaves or microwaves; and in 2004, HCWH helped the Philippines Department of Health prove that it was possible to manage the waste from a country-wide vaccination program without resorting to open burning or incineration.

Several cities across Argentina have also banned or restricted incineration.

• 2006: the municipality of General Pueyrredón in Buenos Aires Province and Villa Regina, in Rio Negro Province both banned incineration.
• 2005: the cities of Rio Grande, Ushuaia and Tolhuin in the Tierra del Fuego province banned the construction of new incineration plants. In the same year, the city of Rosario in Santa Fe province prohibited the incineration of pathological waste and the contracting out of the treatment of these wastes to other jurisdictions.
• 2004: The city of Esquel in Chubut province prohibited the incineration of all types of waste and Villa Allende, Marcos Juarez, both in Córdoba province banned incineration.
• 2002: Buenos Aires banned medical waste incineration.

HCWH first published a guide to non-incineration technologies and how they work in 2001. It was updated in 2004 (pdf). The most widely used technologies are autoclaves and microwaves which use heat to kill microbes in waste, after which it can be disposed of with ordinary municipal waste.

The alternative technology report was followed by an inventory of alternative medical waste technology suppliers around the world: For Proper Disposal (pdf). We identified 113 companies supplying to sixty countries. We will continue to update this inventory periodically. Manufacturers wanting to have their products included should email rstringer@hcwh.org.

On top of the environmental benefits, alternative technologies are usually more economical than incineration. The World Health Organisation has developed an Expanded Costing Analysis Tools (ECAT) to help decision makers working at the facility, district or national level compare the capital and operating costs of the various options.